(navigation image)
Home American Libraries | Canadian Libraries | Universal Library | Community Texts | Project Gutenberg | Children's Library | Biodiversity Heritage Library | Additional Collections
Search: Advanced Search
Anonymous User (login or join us)
Upload
See other formats

Full text of "Text Book Of Mechanical Engineering"

904

Appendix IL

To avoid the evils of varying boiler pressure, a reducing valve
is now often used between boiler and cylinder, giving a lower
pressure, but steadiness and dryness, Reid's valve, Fig. 864, is a

good example. The steam entering at A, finds valve B closed by
spring c, so passes along E, and lifting the throttle valve F, acts
on the piston D and overcomes the compression of spring c, thus
allowing a free flow through D to G at a lower pressure. Now
the coiled pipe L is connected to vessel M, which is always full of
condensation water, and the low pressure acting on diaphragm N
tends to lift lever i and close valve r, thus throttling the pressure
on D to the right amount. The lifting tendency is also resisted
by the spring H, which can be screwed up against a scale K to give
and shew the required reduction.

When the hot-well water is returned to boiler, there is danger
due to the deposition of cylinder oils on the furnace crowns,
causing possible overheating. Feed-water Filters have been there-
fore introduced, of which Rankine's, Fig, 865, is an example.